This invention relates to a metering flow device for loading and conveying machines. Broadly, such machines utilize a front end implement to gather rock, sand, ore or other loose material and transfer it to a self-contained conveyor for transport to a discharge location, usually disposed at the rear of the machine. These machines are often vehicular in nature and find extensive use above ground and also in tunneling.
In some instances, it has been found desirable to use a front end implement which is scoop-shaped. Such an implement is forced horizontally into the loose material to thereby gather a quantity thereof, and is then raised to above the front end of the conveyor where it dumps the material onto the conveyor.
It has been found that if the scoop has too large a capacity in relation to the conveyor, the act of dumping the entire scoop contents at one time can overload the conveyor, causing jamming or damage. In addition, if the pile of loose material being gathered is relatively low, it may be difficult to fill the scoop to capacity for dumping.
The present invention is based on a unique solution to the above-mentioned difficulties.
In accordance with one aspect of the invention, the scoop is open-ended; that is, it is open at both its front and rear. Furthermore, the open rear end of the scoop abuts a curved backstop plate having a center of curvature on the axis about which the scoop is raised or lowered. In addition, the lower portion of the backstop plate is fixed to the machine, while the upper backstop portion normally abuts the lower portion but is selectively raisable to form a gate which meters the flow of gathered material from the open rear end of the raised scoop onto the conveyor.